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by rhodey
116 days ago
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Attestation always involves a "document" or a "quote" (two names for basically a byte buffer) and a signature from someone. Intel SGX & TDX => signature from intel. AMD SEV => signature from amd. AWS Nitro Enclaves => signature from aws. Clients who want to talk to a service which has attestation send a nonce, and get back a doc with the nonce in it, and the clients have somewhere in them a hard coded certificate from Intel, AMD, AWS and they check that the doc has a good sig. |
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In a real attestation scheme you would do something like have the attesting device generate a hardware-backed key to be used for communications to and from it, to ensure it is not possible to use an attestation of one device to authenticate any other device or a man-in-the-middle. Usually for these devices you can verify the integrity of the hardware-backed key as well. Of course all of this is moot though if you can trick an authorized device into signing or encrypting/decrypting anything attacker-provided, which is where many systems fail.